Answer:
Explanation:
The given time is 1 / 4 of the time period
So Time period of oscillation.
= 4 x .4 =1.6 s
When the block reaches back its original position when it came in contact with the spring for the first time , the block and the spring will have maximum
velocity. After that spring starts unstretching , reducing its speed , so block loses contact as its velocity is not reduced .
So required velocity is the maximum velocity of the block while remaining in contact with the spring.
v ( max ) = w A = 1.32 m /s.
Answer:
Option C is the correct answer.
Explanation:
Considering vertical motion of ball:-
Initial velocity, u = 2 m/s
Acceleration , a = 9.81 m/s²
Displacement, s = 40 m
We have equation of motion s= ut + 0.5 at²
Substituting
s= ut + 0.5 at²
40 = 2 x t + 0.5 x 9.81 x t²
4.9t² + 2t - 40 = 0
t = 2.66 s or t = -3.06 s
So, time is 2.66 s.
Option C is the correct answer.
If both bars are made of a good conductor, then their specific heat capacities must be different. If both are metals, specific heat capacities of different metals can vary by quite a bit, eg, both are in kJ/kgK, Potassium is 0.13, and Lithium is very high at 3.57 - both of these are quite good conductors.
If one of the bars is a good conductor and the other is a good insulator, then, after the surface application of heat, the temperatures at the surfaces are almost bound to be different. This is because the heat will be rapidly conducted into the body of the conducting bar, soon achieving a constant temperature throughout the bar. Whereas, with the insulator, the heat will tend to stay where it's put, heating the bar considerably over that area. As the heat slowly conducts into the bar, it will also start to cool from its surface, because it's so hot, and even if it has the same heat capacity as the other bar, which might be possible, it will eventually reach a lower, steady temperature throughout.
Answer:
The lever arm could decrease or increase depending of the initial angle.
Explanation:
The lever arm d is calculated by:
d = rsin(θ)
where r is the radius and θ the angle between the force and the radius.
So, the increse or decrees of d depends of the sin of the angle θ, if the initial angle is greather than 90° and the angle decrease to an angle closer to 90°, the lever arm will increase but if the initial angle is 90° or lower and the angle decrease, the lever arm will decrease.
Answer:
Generally, magnets are attracted to objects that are made of the metals iron, nickel, or cobalt. These materials are called ferromagnetic materials. ... When all or most of the domains are aligned in the same direction, the whole object becomes magnetized in that direction and becomes a magnet.
Explanation:
